6 or more electric buses lost in fire at Potters Bar

[Tim Williams]

SEC_105616755.jpg (99.13 KiB) Viewed 2523 times

This happened 3 days ago. The buses burnt out were both full electric and hybrid fairly new red double deckers of Metroline (a TFL contractor) at their Potters Bar Depot, north of London. Buses are parked close together in depots, especially in the UK and Europe, where land use is at a premium and costs are high, so a bus fire in depots does often result in multiple bus losses.

There certainly have been some problems with lithium batteries (some electric MB Citaros were lost in a fire in Germany, a little while ago!) - I think that technology still has a way to go, to ensure full safety of electric vehicles. I do believe that people who have electric cars that are garaged and charged in a garage that is under the main house roof are taking an unneccessary risk.

The brief news item below has been taken from a local newspaper:

"The incident at Potters Bars saw a bus explode ‘into a ball of flames’
At least four buses caught fire in London after reports of a huge explosion at a transport depot.
Video showed an inferno engulfing a number of vehicles at the Metroline bus garage earlier today.
Eyewitness Shaun Cunningham told the BBC that he had heard an ‘unbelievable noise that sounded like a jet’, adding that he saw a bus explode ‘into a ball of flames’.
Reports suggest no injuries have been confirmed so far – amid suggestions that the incident could have been far worse.
One worker at the site, who did not want to be named, suggested to Metro.co.uk that the fire was extremely close to fuel lines that could have caused further explosions.
‘The cause of the fire was from the charge pack (this charges the electric buses) blast and as a result six buses caught fire’, they claimed."

[Merc1107]

Ouch.

I wonder what role fast or flash-recharging solutions have to play in these sorts of incidents; as they'd likely put a lot of stress on the various electrical components, and generate a lot of heat.

[Tim Williams]

Yes, fast charginng would generate more heat and that may have played a part in this. I still worry about batteries themselves - Tesla cars, for example, have had a number of well publicised and spectacular fires.

We have solar roof panels at home and the suppliers have pushed on a number of occasions for us to buy and have fitted on one of our external walls, a lithium battery, for storing and using the excess power generated - we keep refusing on the basis of reported fires from these batteries.

[Merc1107]

Yes, fast charginng would generate more heat and that may have played a part in this. I still worry about batteries themselves - Tesla cars, for example, have had a number of well publicised and spectacular fires.

It would be useful to know how these fires started - is it an issue with the batteries themselves (the push for cheaper and more energy-dense battery cells), or has some other electrical fault evaded safety mechanisms and caused an overload or thermal runaway?

It's important these sorts of issues are resolved. Perth had a rather unfortunate spate of fires in the OC500LE CNG buses - none of which, per my understanding, were attributable to CNG. The media, however, have not forgotten the P.R. headache they originally caused, and in each subsequent fire on a bus it hasn't been uncommon to hear "Authorities have/have not yet confirmed informed whether or not this was a gas bus".

Anyway, the point is, if the appropriate protocols are not established now in the embryonic stages of electric/hydrogen bus rollouts in terms of dealing with electrical faults, damaged batteries, leaking hydrogen, and so on, we're going to end up with something as catastrophic as the underground Perth Busport or Brisbane's Busway Underworld™ being on fire. The sort of P.R. disaster associated with a high-profile incident like that could cause untold harm to the 'green transport' idea, emerging Australian manufacturers and the outfits that procure those vehicles.

[Tim Williams]

If any of you are interested in this just go to Youtube and type "Electric Bus Explosion Paris" of "China" and either video clearly demonstrates the ferocity of explosions and the intense fire that follows, which were Lithium batteries in the roof of the small RATP bus. There are lots of videos on the subject on Youtube, explosions and fires are really not a rarity. Apparantly 55 small electric buses were lost to fire etc. in a single event at a theme park in China!

Lithium batteries have be constructed to a very high standard and housed in a totally sealed container - if the batteries are damaged, or water into them and/or if they are charged or discharged to quickly, then they can explode. GM, Tesla and others have ongoing substantial re-calls on EV's.

I do hope that the local bus manufacturers have done their homework thoroughly!

[Merc1107]

A video of the incident in Paris was shared in the NSW Electric Bus Plan thread. I wonder how much indication there was prior to that catastrophic fire that something was amiss, and what the official time taken for the fire to consume the bus (as I assume the footage has been edited for more dramatic effect)?

It would certainly be far from ideal attempting to evacuate a bus through the shower of flames... No escape via the roof due to the equipment up there. Take the Volvo BZLs in Perth, I think it was just two or three emergency exit points (breakable glass) besides the doors. In comparison, I note buses with Brisbane Council have multiple hammers fitted (three or more each side, plus roof hatches, on a diesel Volvo artic, for instance), and diagrams in place to show all possible escape points.

[ScaniaGrenda]

Merc1107 raises a very valid point, after he raised the point It got myself thinking in such a situation what is the most effective way to evacuate the bus in such an event.

Let's say there's an electric bus where the equipment in this scenario isn't fitted to the roof & like most of the other E-Buses here is fitted normally where the engine would go in a diesel bus. Fire breaks out, what's the most sensible way to get out quickly;

Roof Hatch - Honestly I wouldn't even attempt to exit through the roof as the bus isn't on it's side for starters and you do have to make a considerable jump back to the ground from the top of the bus and the bus is quickly becoming engulfed in flames & time is critical. I don't 100% recommend this way out especially with less able passengers.

Window hammers - the 2nd best option but would you trust someone to know where to properly break the glass in such a time critical situation? There'd be a lot of panic and rush rush to try and get the window broken and you do run the risk of cutting yourself on sharp bits of glass in the process. If the doors on the bus are still accessible I wouldn't recommend the window.

The Doors - In any case of fire, definitely the best way to go. Just takes the EDR (Emergency door release) being activated / pushed and sliding the door(s) open manually and getting as far away from the bus as possible. Process if it goes to smooth should take less than 20 seconds (not accounting for everyone at once trying to push their way out)